/Engine/Source/Runtime/InteractiveToolsFramework/Public/BaseGizmos/GizmoRenderingUtil.h
OutWorldFlattenScale vector to be applied in world space, can be used to flatten excluded dimension in orthographic views as it reverses the scale in that dimension.
namespace GizmoRenderingUtil { float GizmoRenderingUtil::CalculateViewDependentScaleAndFlatten ( const [FSceneView](API\Runtime\Engine\FSceneView) * View, const FVector & Location, const float Scale, FVector & OutWorldFlattenScale ) }